Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: settlement via USDC/x402 on specific chains, the return of a subscription_id, and a significant caveat: 'Backend pending (Q3 2026).' This addresses operational status and limitations, though it does not cover authentication or delivery mechanism details.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded with the core action ('Subscribe to threshold-triggered oracle notifications'). It includes essential context (chains, settlement, return value, backend status) in just two sentences, with every detail earning its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (2 parameters, no output schema, no annotations), the description provides sufficient context: it explains what the tool does, what to expect as a return value, and even flags backend unavailability. This is complete for an agent to decide and invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides full descriptions for both parameters (symbol and threshold) with 100% coverage. The description does not add additional semantics beyond what the schema states, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'Subscribe to threshold-triggered oracle notifications for a symbol.' This specific verb+resource phrasing distinguishes it from sibling tools like get_price and list_feeds by focusing on the notification subscription action. It also mentions the return value and supported chains, reinforcing the purpose.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context that this tool is for setting up threshold-based notifications, which implies when to use it (when you need alerting on price thresholds) versus siblings that fetch prices or list feeds. However, it does not explicitly state alternatives or exclusions, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.